1 files changed, 74 insertions, 0 deletions
diff --git a/recipes-demo/de10-nano-gpio-apps/files/watch_switch_events_ioctl.c b/recipes-demo/de10-nano-gpio-apps/files/watch_switch_events_ioctl.c
new file mode 100644
index 0000000..cd78363
--- /dev/null
+++ b/recipes-demo/de10-nano-gpio-apps/files/watch_switch_events_ioctl.c
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <error.h>
+#include <errno.h>
+#include <limits.h>
+#include <unistd.h>
+#include "linux/input.h"
+
+int main(void) {
+	int event_dev_fd;
+	const char *path = "/dev/input/by-path/platform-soc:base-fpga-region:keys-event";
+	struct input_event the_event;
+	int result;
+	unsigned char keys[9];
+	
+	// open the event device node
+	event_dev_fd = open(path, O_RDONLY | O_SYNC);
+	if(event_dev_fd < 0)
+		error(1, errno, "could not open file '%s'", path);
+	
+	while(1) {
+		// read the next event
+		result = read(event_dev_fd, &the_event, 
+				sizeof(struct input_event));
+		if(result < 0)
+			error(1, errno, "reading %d from '%s'", 
+					sizeof(struct input_event), path);
+		if(result != sizeof(struct input_event))
+			error(1, 0, "did not read %d bytes from '%s'", 
+					sizeof(struct input_event), path);
+		
+		// if the event is EV_KEY, then process it, otherwise ignore it
+		if(the_event.type == EV_KEY) {
+
+			// look for the codes that we expect
+			switch(the_event.code) {
+			case(KEY_F6) :
+				printf("SW0");
+				break;
+			case(KEY_F7) :
+				printf("SW1");
+				break;
+			case(KEY_F8) :
+				printf("SW2");
+				break;
+			case(KEY_F9) :
+				printf("SW3");
+				break;
+			default :
+				printf("unknown");
+				break;
+			}
+			
+			// output the value of the event
+			printf(" moved to value '%d'\n", the_event.value);
+
+			// read the current state of the keys
+			result = ioctl (event_dev_fd, EVIOCGKEY(sizeof keys),
+					&keys);
+			if(result < 0)
+				error(1, errno, "ioctl from '%s'", path);
+			
+			printf("SW0(%d) SW1(%d) SW2(%d) SW3(%d)\n",
+					(keys[8] & 0x01) ? (1) : (0),
+					(keys[8] & 0x02) ? (1) : (0),
+					(keys[8] & 0x04) ? (1) : (0),
+					(keys[8] & 0x08) ? (1) : (0)
+				);
+		}
+	}
+}
+